Pneumatic-hydraulic pressure converter



March 7, 1950 E. M. PFAUSER PNEUMATIC-HYDRAULIC PRESSURE CONVERTER Filed D60. 8, 1945 mm R x m m UNITED STATES PATENT. OFFICE P UMATIC-HYDRAULIC PBESSVUBE CO VERTER.

Edward M. 'Pfauser, Elm Grove, Wis., assignor to -Blackhawk Mfg. (30., Milwaukee, Wis a cor poration of Wisconsin Application Decemberf8, 1945 Serial No. 633,705

4- Claims. Cl. 60-545) This invention relates generally to improvements in systems for transmitting pressure from supply sources to zones of utilization, and relates more specifically to an improved pneumatically actuated hydraulic ram assemblage. 5 acters designate the same or similar parts in the The primary'object of my invention is to provarious views. vide an improved fluid pressure actuated ram as- Fig. 1 is a somewhat diagrammatic side elevasemblage which is simple and compact in conti n of a ypi al pn m i lly a d hystruction, and which is moreover highly efficient draulic ram assemblage embodying the invenin operation and flexible in its adaptations. tion;

In commercial garages and other institutions Fig. 2 is an enlarged longitudinal central verwhere abundant air under pressure is avai able, tical Sectionthrough the improved pressure conit is frequently desirable to also have available vertor for transforming the air pressure into hyfor immediate use, rams or similar pressure apdraulic pressure; and plying devices which are adapted to be operated 162 Fig. 3 is an enlarged central vertical section from the air pressure supply source and which are through the control valve of the system, showing also relatively compact but powerful and adapted the valves in reverse position as compared to to be actuated in any position and in cramped the disclosure in Fig. 1. localities. Relatively small and universally mov- While the invention has been shown and de-. able hydraulic rams are best suited for such pur- 'scribed herein as being especially applicable to poses, but it is desirable in order to permit una portable unit for pneumatically actuating obstructed use of such rams, to provide portable simple hydraulic rams with the aid of air underpower transmitting means for converting the air pressure, it is not my desireor intent to thereby pressure from the source of supply into hydraulic unnecessarily restrict the utility of the invention pressure within the ram; and to also provide since some of the improved features may be more readily manipulabl'e control means for effecting generally applicable. normal operation of the system. No system for Referring to Fig. lot the drawing, the imefiectivey accomplishing these desirable results proved typical pneumatically actuated hydraulic has heretofore been commercialized without inram system shown therein, comprisesin general" troducing many complications. any suitable source or supply of air under pressure It is therefore a more specific object of-the pres-' such as a pipe line 5 communicating with a coment invention to provide an improved system of pressor or storage reservoir; a pressure converter the above-mentioned type, which most effectively and transmitter 6' for transforming air pressure meets all requirements and which is in' fact ex derived from the'pipe line 5 into hydraulic press ceedinaly reliable in operation; '35 sure; a control'valv'e' assemblage l interposed at;

Another specific object of this invention is'to' any convenient location between the pipe line 5 provide an improved'unit for effectively convert and the converter 6': an'd'a hydraulic ram 8 oping air pressure into hydraulic pressure incon-J' erabe by hydraulic pressure derived from the centrated form, and which'is universally movable converter 6. and highly attractive in appearance. 40 The'improved pressure converter 6 is prefer- A further specific object of the invention is to ably of light but durable and portable construcprovide improved ram actuating and control tion as shown in detail in Fig. 2, and consists mechanism which is conveniently"manipulable" primarilyof'a'f'triple section streamlined casing for the purpose'o'f performing diverse classes of comprising front and rear and intermediate dowork. axial sections 9, in; 'H' respectively; an air pres,

Still another specific object of my invention is sure-actuated piston |'2- slidablewithin a relatively to provide a durable pneumatically actuated hylarge air'cylinder l3 firmly but'detachably condraulic ram unit, which is flexible in its adaptanecting the end casing sections 9,18; a hydraulic tions and which may be manufactured and sold pressure transmitting piston l4 slidable within a at moderate cost. 5o relatively'small'hydraulic cylinder l5 d'etachably These and other specificobjeots 'and advantages mounted.- in the forward portion of the front of the invention will be apparent'fron'i 'thefoI-. casing sec f1 by meansof'a fitting l6, and bee lowing detaileddescription. ing;.releasably'conrrectedIto"theJairpiston 1.2,: by a A clear conception of the several features can; pistonrodli; and ahelical compression spr'i, g, stituting my present invention; and of the con-.. '66 l8Ilooselyisurroundingthercylinderl5- cos;

struction andoperation of a typical system em-v bodying the same, may be had by referring to the drawing accompanying and forming a partof this specification wherein like reference char-'- acting at its opposite ends with the air piston l2 and casing section a respectively.

The cylinders l3, 15 are of approximately the same length and may be formed of light but durable tubing of proper internal diameter, and the rear casing section In is provided with a central air inlet port I9 with which the control IO near the port' able with the front casing section 9 in order to limit the forward piston stroke as shown in solid lines in Fig. 2. The rear casing section 9 and the port l9 are in constant open communication with the rear displacement chamber of the air cylinder I3; and the front casing section 9 within which the spring I8 is confined, should be provided with an air vent 23.

The opposite ends of the tubular air cylinder l3 have screw thread coaction with the adjacent ends of the front and rear casing sections 9, l9,

and these threaded cylinder ends serve to firmly clamp the intermediate casing section I 1 between the two end sections 9, I; and the front end of the hydraulic cylinder l5 has screw thread coaction with the fitting I6 which is attached by other screw threads to the forward end of the front casing section 9. The entire converter unit is thus adapted to be readily assembled or dismantled, and the fitting I6 is provided with a liquid conducting port 24 adapted to be connected to the ram 8 by means of a staunch but flexible high pressure hose of any suitable length. The hydraulic piston 14 is provided at one end with a cup-packing 2B which is exposed to the port 24, and this piston is snugly slidably cooperable with the bore of the cylinder 15, and is also provided at its opposite end with a spherical socket with which the ball-shaped front end 21 of the piston rod I1 is releasably cooperable. The rod I1 is loosely slidable within the hydraulic cylinder I5,

and has its rear end 28 threaded for rigid attachment to the air piston l2 with the air of a lock nut 29. With this assemblage of elements, the hydraulic piston I4 may move within the cylinder l5 independently of the air piston 12, *and not be drawn rearwardly by the air piston when the latter moves rearwardly, since the rod end i 21 is adapted to be withdrawn from the socket within the hydraulic piston 14. This releasable connection between the spherical end 21 of the rod I! and the hydraulic piston l4 permits the air piston l2 to be forced by the spring l8 to the extreme right as viewed in Fig. 2, upon release of the air pressure acting upon the piston l2, without correspondingly moving or withdrawing the piston l4 and thereby creating a vacuum in the hydraulic system such as might cause air to be admitted and trapped within this system; and the releasable connection also permits the piston l4 to be readily removed from the cylinder l5 for re-packing without disturbing the rod l1 and piston 12.

In order. to

medial casing section H is provided with" a carrying handle 30, and the-sections H, 9'may also be will facilitate transportation and manipulation of the pressure transmitter 6, the,

provided with a shoulder strap 31 as shown. In addition to the handle 30 and strap 3!, the converter unit casing may be provided with a pair of front supporting wheels 32 associated with the front section 9, and with a central rear skid block 33 secured to the intermediate section I I, or with additional wheels 32 in substitution for the block 33. These supports will permit the operator to pull the converter 6 along the ground with little effort when the ram 8 is being utilized in cramped quarters remote from the fixed air supply line 5.

As previously indicated, the improved control valve assembly I may either be mounted directly .upon the rear casing section In adjacent to the port 19, or the control valve may be mounted on a flexible branch air supply hose 34 and connected to the port 19 by a flexible hose or tube 20, and the details of the control valve assemblage are disclosed in Fig. 3. This control valve assemblage I is very simple and compact and comprises merely a body 35 having opposed passages 36, 31 in its opposite ends and an air escape port 38 near the passage 31; and two similar manually opened spring closed poppet valves 39, 49 interposed between the passages 36, 31 and between the passage 31 and the port 38 respectively. The valve 39 is an air pressure inlet control valve. and is provided with an actuating stem and button 4|, being normally urged toward closed position by a compression spring 42 and air under pressure coacting with the valve and with a screw plug 43. The valve 49 is an air pressure exhaust valve, being provided with another actuating stem and button 44 and likewise being normally pressed to its seat by a compression spring 45 and back pressure coacting therewith and with another screw plug 46. The two valve chambers are interconnected by a conduit 41 and the stem of the valve 39 is preferably provided with a packing 48; and the valve arrangement is such that when the valve 39 is opened. air under pressure will be admitted to the converter 6 from the passage 35 through the conduit 4! and passage 31 while the valve 40 remains closed. whereas opening of the valve 40, while the valve 39 remains closed, will cause compressed air from the converter 6 to escape to the atmosphere through the a sa e 31 and port 38.

The hydraulic ram 8 which is operable by liouid under pressure delivered from the converter 6 by the piston I4 through the fitting port 24 and hose 25, is of relatively simple construct on and com rises primarily a universally movable cylinder 49, and a ram plunger 50 slidably confined ;within the cylinder 49. The ho e 25 communicates with the closed end of the plun er displacement chamber remote from the movable plunger,

and if so desired, the ram plunger 50 ma be cylinder 49 will be compressed and will tend to move the plunger 50 outwardly, whereas application of pressure to the ram plunger 50 when the piston I4 is released, will cause this piston M to be moved rearwardly within the cylinder l5.

When the improved pneumatically actuated hydraulic ram system has been properly constructed and assembled as in Fig. 1, the controlvalves 39, 40 will normally be closed, and the converter 6 and ram 8 may be moved about freely and disposed in any desired position. The

5 ram plunger 5t!- and cylinder t9 may then be transposed between anv objectto which pressure is to be applied and any suitable reaction .5111.- face, whereupon pneumatic pressure may be admitted to the air piston l2 by merely i'opening the valve 39 with the aid ofthe push-button. As-the air pressure acts upon the piston. 12 it compresses the spring l8 and forces the hydraulic piston M forwardly through the piston rod I 1, thereby subjecting the hydraulic system: to .high pressure and causing the ram. 8- to do its work. When it becomes desirable torelease thepressure within-the ram 8, it is. only necessary: torelease the button 4| and to press the button 44, whereupon the spring d2 will close the valve 39 and prevent further ingress of compressed air, while the open valve140"willpermitrair to escape from the converter through the tube 20, passage 3.! and port 38, to the atmosphere. Release. of both buttons 4 l, 44' will again place the-apparatus in normal condition, and it is to be observed that when the air pressure from within the converter 6 is released, the spring I 8 quickly becomeseifective to move the piston I2 into its rearmost position,

without affecting the position of the hydraulic piston l4. However, when the piston [2 has been thus withdrawn, application of pressure to the ram plunger 50 will cause the hydraulic piston Hi to move rearwardly within the cylinder l5.

From the foregoing detailed description, it will be apparent that my present invention provides a new and useful pneumatic hydraulic ram system which is exceedingly simple and compact in construction and which is moreover highly efiicient in operation and flexible in its adaptations. The converter unit 6 and the ram 8 may obviously be readily transported and disposed in any desired position, and the pressure transmitter functions to effectively convert relatively low pneumatic pressure into high hydraulic pressure at the ram 8. The converter 6 besides being of highly aesthetic appearance and readily transportable and manipulable, may be quickly assembled and dismantled so as to gain access to all portions of the apparatus, and the control valves 39, 40 being of simple and interchangeable construction, reduce the cost of manufacture of the assemblage to a minimum. The releasable connection between the air piston l2 and the hydraulic piston I 4 eliminates the possibility of having air enter the hydraulic system, and the vent 23 serves to positively prevent confinement of air in front of the air piston l2. The fitting l6 besides providing a rigid support for the hydraulic cylinder I5, permits convenient removal of this cylinder and of the hydraulic piston I 4 therein, and all parts of the apparatus are of durable construction and may be manufactured at moderate cost. The use of the thin tubular section II and cylinders l3, l5, provides a light but strong portable structure in which the section II efiectively protects the thin cylinder against possible indentation or damage due to rough usage. The improved ram system has proven highly satisfactory in actual use and can be utilized to perform diverse types of work.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of operation herein. shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

I claim:

1. A pneumatic-hydraulic pressure converter comprising, an elongated casing having coaxial opposite end sections and attain-tubular intermediate sectionloosely abutting the adjacenttion and having its opposite ends screw-threaded within said end sections to unitethe latter and to clamp the intermediate section in place, a hollow fitting detachably secured to the extreme end of one of said end-sections remote from said air cylinder, a thin tubular hydraulic cylinder of lesser diameter than the interior of'said air cylinderand the exterior of said fitting secured to. and supported at one end from the fitting while its opposite free end" extends centrally within the air cylinder, and cooperating air and hydraulic pistons slidable in said air and hydraulic cylinders respectively.

2. A pneumatic-hydraulic pressure converter comprising, an elongated casing having coaxial opposite end sections and a thin tubular intermediate section surrounding and loosely abutting the adjacent ends of the end sections, a thin tubular air cylinder disposed within and spaced from said intermediate section and having its opposite ends screw-threaded within said end sections to unite the latter and to clamp the intermediate section in place, a hollow fitting detachably secured within the extreme end of one of said end sections remote from said air cylinder, a thin tubular hydraulic cylinder of lesser diameter than the interior of said air cylinder and the exterior of said fitting secured to and supported at one end from the fitting while its opposite free ends extends centrally within the air cylinder, and cooperating air and hydraulic pistons slidable in said air and hydraulic cylinders respectively.

3. A pneumatic-hydraulic pressure converter comprising, an elongated casing having coaxial opposite end sections and a thin tubular intermediate section surrounding and loosely abutting the adjacent ends of the end sections, a thin tubular air cylinder disposed within and spaced from said intermediate section and having its opposite ends screw-threaded within said end sections to unite the latter and to clamp the intermediate section in place, a hollow fitting detachably secured within the extreme and of one of said end sections remote from said air cylinder, a thin tubular hydraulic cylinder of lesser diameter than the interior of said air cylinder and the exterior of said fitting secured to and supported at one end from the fitting while its opposite free end extends centrally within the air cylinder, an air piston slidably cooperable with said air cylinder, a hydraulic piston slidably cooperable with said hydraulic cylinder, and a piston rod snugly slidably engaging said hydraulic cylinder and having one end rigidly attached to said air piston while its opposite end loosely contacts said hydraulic piston.

4. A pneumatic-hydraulic pressure converter comprising, an elongated outer casing having coaxial opposite cup-shaped end sections and a thin tubular intermediate section surrounding and loosely abutting the brims of the end sections, a thin tubular air cylinder disposed within and spaced from the interior of said intermediate section and having its opposite end screw-threaded within said cup-section brims to unite the latter and to clamp-[the intermediate section against the end sections, a hollow fitting detache ably screw threaded within the base of one of said cup-sections remote from its brim, a thin tubular hydraulic cylinder of lesser diameter than the interior of said air cylinder and the exterior of said fitting secured to and supported at one end from the fitting while its opposite free end extends centrally into the air cylinder, 9. cup-shaped air piston having its brim slidably cooperable with said air cylinder while its base is movable into the other of said cup-sections, a piston rod having one end rigidly secured Within the base of said cup-shaped piston and being snugly slidably cooperable with said hydraulic cylinder, and a hydraulic piston slidable within said hydraulic cylinder and loosely abutting the opposite end of said piston rod. 6

. EDWARD M. PFAUSER.

8 9 REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Caskey Nov. 20, 1906 White Aug. 2, 1932 Johansson Apr. 11, 1933 Huck Sept. 8, 1936 Martin Aug. 9, 1938 Boldt June 30, 1939 Freeman Sept. '7, 1943 Rockwell Mar. 20, 1945 Swenson Feb. 19, 1946 FOREIGN PATENTS Country Date France May 28, 1927 

